Mirena (levonorgestrel-releasing intrauterine device) and NuvaRing (etonogestrel and ethinyl estradiol vaginal ring) are forms of birth used to prevent pregnancy.
Mirena is a hormone-releasing system placed in your uterus (intra-uterine device, or IUD) to prevent pregnancy for up to 5 years. NuvaRing contains a combination of female hormones in a flexible contraceptive vaginal ring used to prevent pregnancy.